Lesson plan 17 Our Earth Under Threat

Reading and taking measurements Overview from a graph.

Speed, distance, This activity is designed as a ‘virtual and time. mission’. Students will play the part of Calculating time Near Earth Asteroid (NEA) scientists to the given a speed and scenario of a possible asteroid impact with distance. 14-16 the Earth. By following the story of the Making mission (led by an automated powerpoint), measurements. students will apply their understanding of kinetic energy, density and probability to Gravity, weight and mass. perform calculations and research possible methods of deflecting the asteroid.

This mission is decision based – at several curriculum links points they will have to make decisions about how to tackle the asteroid, and the outcome for each group will depend on the decisions that they have made.

What you need Starter 5 Run through the briefing PowerPoint mins Laptop with “Our Earth and explain to the students that in Under Threat” PowerPoint groups, they will work through the running and internet access simulated scenario to apply the (one per group) physics that they have learnt to the protection of the planet. Also point out 17.1 Earth Under Threat that at every step, there will be hints student sheet (one per that they can click on to help them if they are necessary. student) 17.2 Near Earth Asteroid report (one per student) A17 Earth under threat briefing Powerpoint

58 Our Earth Under Threat Lesson plan

Our Earth Under Threat Our Earth Under Threat 17 Main activity 1 45 Students run through the virtual is the earth mins really mission. under threat? his image shows the differene in the orbits of BORROW THE a tpial NEWS near-arth asteroid (ble) and a potentiall MOON haardos asteroid or (orange)

ROCK ALERT!miles (8 million kilometers) of Earth 4,700 Potentially Dangerous Asteroidsand Lurk are Nearlarge Earth,enough NASA to cause Says damage on regional or global scale if his image shows the difference in they were ever to hit our planet. Tthe orbits of a typical near-Earth According to the survey, about twice asteroid (blue) and a potentially as many asteroids are in so-called haardous asteroid, or PHA lower-inclination orbits which are (orange)A new NASA survey by the more closely aligned with Earths WISE telescope has pinned down the path around the sun than other number of asteroids that could pose objects than previously thought a collision threat to Earth in what researchers said. miles (150 million km) from the sun. scientists say is the best estimate A possible explanation is that many The data from NEOWISE, when yet of the potentially dangerous of the PHAs may have originated combined with other asteroid data space rocks. from a collision between two aster- these targets can provide the best observations, helped NASA announce The survey found there are likely oids in the main belt lying between opportunities for the next generation in 2010 that about 90 percent of the 4,700 potentially haardous aster- Mars and Jupiter," NASA officials of human and robotic exploration. largest near-Earth asteroids that oids, plus or minus 1,500 space explained in a statement. A larger During its asteroid hunt, the WISE come close to our planetSore: had Spae.om been rocks, that are larger than 330 feet body with a low-inclination orbit may telescope searched for space rocks identified. (100 meters) wide and in orbits that have broken up in the main belt, within about120 million miles (195 occasionally bring them close causing some of the fragments to million km) of the sun. For compari- enough to Earth to pose a concern, drift into orbits closer to Earth and son, the Earth is about 93 million researchers said. To date, only about eventually become PHAs. 30 percent of those objects have Because they will tend to make actually been found, they added. more close approaches to Earth, Potentially haardous asteroids, or PHAs in NASA-speak, are space rocks in orbits that come within 5 million A17 Earth under threat PowerPoint 17.2 NEO report

ACTIVITY17 .1 earth under threat! task 3: Calculating the kinetic ACTIVITY 17.1 earth under threat! energy of the object task 1: what is a pha? task 2: what type of asteroid?Kinetic Energy oules) task 2: Read through the report on potentially hazardous asteroids Using the information you have been given, calculatehere m the mass density in kg and v velocity in metres1 per second Click on the link in thewhat console DO panel WE and researchDO? three methods (PHAs) and answer the questions below: of the object to determine the type of PHA that we are dealing mv 2 of dealing with the threat. Briefly summarise the methods below with. The circle the type of object below and make your selection 2 and use this to help you make a choice as to your course of action. What is the definition of a Potentially Hazardous Asteroid (PHA)? on the mission screen. 1 Megaton 4.18 x 10

15 Kinetic energy in oules Method Density = How it works Kinetic energy in megatons How many PHAs are thought to be in orbits that would cause concern? Pros and cons TI SCAL ATIG Stony meteorite Stony-iron meteorite Iron meteorite density range: density range: density range: 3000– 5000– 7000– 3 3 3 Where is it believed many of these PHAs originated from? 3700kg/cm 5600kg/cm 8000kg/cm

Initial parameters of object: Mass = earth under threat! Radius = 17.1 Earth under Probability of impact =

earth under threat! ACTIVITY 17 threat

ACTIVITY 17

we should invest more time and money into Plenary researching the risk of NEAs? If students have time, they can spend 10 Ask the students what the outcome of some time at the end of the lesson using mins their mission was and run through the the Down2Earth impact calculator (linked answers on the powerpoint. Did they to in their powerpoint) to investigate experience any problems? Do they think impacts on the Earth.

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